Sewing machine



1936- c. E. COLEGROVE ET AL 2,056,829

SEWING MACHINE Filed March 31, 1935 El-t M 6m maw 0 M wag 2 m Patented Oct. 6, 1936 UNITE STATES P TENT OFFICE SEWING MACHINE Charles E. Colegrove, Lakewood, and Casper J. Dorer, Cleveland, Ohio Application March 31, 1933, Serial No. 663,724

3 Claims. (Ci. 112-218) This invention relates to improvements in sew ing machines, and has to do principally with a bobbin winding mechanism and means for driv ing it from the power shaft of the machine.

One of the objects of the invention is the provision of a bobbin winding mechanism which shall be largely e nclosed within and concealed by the machine head, in order to enhance the appearance of the anism.

machine and to protect the mech- Another object of the invention is the provision of a drive for a bobbin winding mechanism which shall be adaptable to use with a motor enclosed within the hollow arm of the sewing machine.

A further object is the provision of a bobbin mechanism which shall be made as a unit for convenience in in assembly.

servicing and replacement, as well as Still another object is the provision of means for automatically disengaging the bobbin winding mechanism when the bobbin has been filled to applied.

Fig. 2 is a transverse horizontal sectional view on a larger scale, the view being taken substantially on the line 2-2 of Fig. 1.

Fig. 3 is a fragmental vertical sectional view taken substantially on the line 33 of Fig. 2.

Fig. 4 is a detail sectional view taken substantially on the line 4-4 of Fig. 2.

Fig. 5 is a fragmental elevational view of the outer portion of the bobbin winding unit, and

Fig. 6 is a detail elevational view of a modification.

In Fig. 1 of the drawing we have illustrated a sewing machine head having a hollow base or bed It! and a hollow arm or gooseneck comprising a vertical portion ii and a horizontal portion l2. Within the vertical portion 12 of the hollow arm there is an electric motor having a rotor I3 carried by vertical motor shaft M which extends for some distance above and below the rotor l3, and

constitutes the power shaft of the machine.

This

shaft may carry a worm l5 which may be clutched to or declutched from shaft H by any suitable means by manipulation of a knob l6 projecting through the top of the hollow arm, as indicated in Fig. 1.

The particular means for clutching and declutching the worm gear I5 to the shaft it per se forms no part of the present invention, and hence need not be illustrated herein..

The worm l5 meshes with a worm wheel (not shown) carried upon a horizontal shaft I! mounted in the horizontal portion i2 of the hollow arm. This shaft-drives the needle mechanism of the machine, and may have a fly-wheel l8 secured to its rear extremity. The shuttle and the feed bar of the machine may be driven by suitable connections from the shaft H, as will be readily understood, and as illustrated in our copending application above identified.

On the lower extremity of shaft it we mount a drive wheel i 9, which is shown as comprising a metallic hub with a flange and collar for hold-, ing a beveled friction disk 20, which we prefer to make of a hard grade of felt.

The bobbin winding mechanism is built as a unit, best shown in Fig. 2, which may be separately assembled and then placed in position in the machine. This unit includes a block 2| which is of a size to be inserted through an opening 22 in the hollow arm i l, and is provided with a flange 23 that abuts against a flat surface surrounding the opening 22 and is secured to the hollow arm by means of screws 24 or the like. The block 2| has a relatively long journal therein which receives a spindle 25. About half way between the ends of spindle 25 there is an integral collar 26 which abuts against the inner surface of the block 2|, while a second collar 21 is secured to the spindle 25 in position to abut against the outer face of the block, these collars holding the spindle against longitudinal movement. The outer extremity of spindle 25 beyond the collar 21 is of a proper size to frictionally receive a bobbin 28. Spindle 25 has a keyway 29 formed therein which slidably receives a stud 30 that is threaded into the hub of a drive wheel 3!. In this instance the wheel 3| is a beveled friction disk of metal, which is adapted to operatively engage the friction disk 20.

The wheel 3| with its elongated hub is slid-. ably mounted on the spindle 25, being urged inwardly or toward the disk 20 by a coil spring 32 which bears at one end upon collar 26 and at the other end against a collar 33 on the hub of the wheel 3i. Just forward of the collar 33 there is a peripheral groove 34.

In an intermediate position on the block 2| there is an inwardly extending bracket 35 in the outer end of which there is mounted a headed pin 36, and upon this pin behind the head thereof is pivotally mounted a lever 31. This lever has a short arm 38 that is adapted to engage against the forward side of collar 33, and a long arm 39 which rests in a slot in the inner end of a plunger 40' that is longitudinally slidable in the block 2| and projects therethrough, being provided on its outer extremity with a knob 4|, by means of which it may be moved lengthwise. A coil spring 42 surrounds plunger 40, bearing at one end against the block 2| and at the other end against a pin 43 mounted in the plunger.

Spring 42, which is stronger than spring 32, tends to push the plunger 40 inwardly and thereby to rock lever 31 upon its pivot so as to cause lever arm 38 to move collar 33 outwardly or rearwardly against the action of spring 32, thereby withdrawing disk 3| from engagement with disk 20.

Upon the outer face of block 2|, somewhat below knob 4| we mount a pin 44 having a smooth shouldered portion which oscillatably supports a flat metal trigger 45. At its lower end this trigger carries an upwardly extending arm 46 that is in the form of a metal strip and is preferably integral with the main part of the trigger, although arranged at an angle of substantially 90 thereto. This arm 46 is of a width to enter readily between the side walls or flanges of the bobbin 28. The upper part of trigger 45 is adapted to enter a notch 41 formed in the shank of plunger 40 behind knob 4|. A coiled wire spring 48 surrounds the shank of the plunger, is anchored at one end in the block 2|, and at the other end has an angular extremity 49 which presses upon arm 46 and tends to turn the trigger as a whole in a clockwise direction as viewed in Fig. 5. When the knob 4| is pulled outwardly to the position shown in Fig. 2, the trigger snaps into the notch 41 and holds the plunger thus retracted against the action of spring 42, which then permits spring 32 to shift the friction disk 3| into engagement with the disk 20.

In Fig. 6 we have shown a different form of driving connection between the shaft l4 and spindle 25 in which we use a bevel pinion 50 pinned to shaft l4, and a bevel pinion meshing with pinion 50 and slidable upon spindle 25 in the same manner as in the case of the beveled friction disk 3|.

Operation.-Normally the upper portion of trigger 45 rests against the base of knob 4|, that is it is out of engagement with notch 41 and the spring 42 is acting to hold plunger 40 in its inner position, in which position the lever 31 is tilted to cause lever arm 38 to pull back drive wheel 3| against the action of the weaker spring 32, thereby effecting a disengagement of the bobbin driving mechanism. At such times there will ordinarily be no bobbin on the exposed end of bobbin spindle 25. Now, if the operator desires to wind at bobbin, he slips one onto the end of spindle 25, the arm 46 not interfering with this operation, since it is held to one side by the engagement of the trigger with the shank of the plunger 40. When the bobbin is in place on the spindle, and the thread started on the bobbin, the operator grasps knob 4| and pulls the plunger 40 outward against the action of spring 42 sufficiently to permit trigger 45 to snap into notch 41. As soon as the pressure of spring 42 upon lever 31 is relieved, spring 32 begins to act, so that as the knob 4| is withdrawn, the drive wheel 3| travels forward toward wheel 26, and by the time the trigger 45 springs into notch 41 the two drive wheels are in effective engagement. At the same time that the trigger 45 enters the notch 41 the arm 46 carried by the trigger enters the space between the flanges of bobbin 28. The op erator now manipulates the motor rheostat to operate the motor at the desired speed and the bobbin turns with the spindle 25. The reeled thread upon the bobbin presently engages the trigger arm 46 and gradually deflects it toward the left in Fig. 5, until finally the trigger is lifted out of the notch 41 in the plunger, when the spring 42 draws the plunger inwardly and rocks lever 31 to retract drive wheel 3|, thereby automatically disabling the winding mechanism when the bobbin is filled. There is nothing further for the operator to do except to withdraw the bobbin from the spindle 25. When the newly wound bobbin is properly positioned in the machine the operator manipulates the knob |6 to again connect the motor with the sewing machine, and work with the machine may be resumed.

Having thus described our invention, we claim:

1. In a sewing machine, a hollow casing, a power shaft therein, said casing having an opening through one wall thereof, a bobbin winding unit adapted to be inserted into or withdrawn from said opening as a unit, means for removably attaching said unit to the casing, a bobbin winding spindle journalled in said unit, and separable operative connections between said spindle and power shaft.

2. In a sewing machine, a hollow casing, a power shaft therein, said casing having an opening through one wall thereof, a bobbin winding unit adapted to be inserted into or withdrawn from said opening as a unit, means for removably attaching said unit to the casing, a bobbin winding spindle journalled in said unit, separable driving connections between said spindle and power shaft, and means mounted in said unit and projecting outwardly therethrough for making and breaking said driving connections.

3. In a sewing machine, a hollow casing, a power shaft therein, said casing having an opening through one wall thereof, a bobbin winding unit adapted to be inserted into or withdrawn from said opening as a unit, means for removably attaching said unit to the casing, a bobbin winding spindle journalled in said unit, separable operative connections between said spindle and power shaft, spring actuated means for disengaging said operative connections, and a trigger mechanism for releasing said spring actuated means, said mechanism comprising an element arranged to engage the reeled thread on a bobbin arranged on said spindle.

CHARLES E. COLEGROVE. CASPER J. DORER. 

